Hammond hears update on FEMA map revision that could remove large areas from flood zone

The Hammond City Council on Jan. 14 heard a status report from Principal Engineering on a Letter of Map Revision (LOMR) submitted to the Federal Emergency Management Agency in November 2024 that would revise local flood insurance rate maps.

Andre Monot, a project engineer with Principal Engineering, told the council the objective was “to revise the flood insurance rate maps within the study area to adjust the base flood elevation,” adding that the goal is to make the maps “better represent physical reality.” He said the firm’s modeling and mapping propose removing some currently mapped special flood hazard areas and tightening limits in other locations.

The change would be material for property owners. Monot explained that LOMRs change where the National Flood Insurance Program requires or recommends flood insurance by altering mapped base flood elevations and the delineation of the special flood hazard area. “The blue shading is the flood zone,” he said while showing the map, and described green zones the team recommends retaining as flood hazard areas and light-blue shaded areas proposed to be removed.

Monot described two technical bases for reductions on the proposed map: a slightly lower estimated flow entering the city from Ponchitula Creek in the firm’s new analysis, and use of a more detailed hydraulic method than FEMA’s earlier, approximate mapping in some locations. He said the study began in 2019, that modeling and draft mapping are complete, and that the application went to FEMA in November 2024. By regulation, he said, “FEMA has 90 days to review and respond,” and that the process is iterative—agency comments typically trigger additional engineering responses and another review window before a preliminary map is published for public comment.

Residents and commissioners raised questions about the study area and whether parcels along the west side of the interstate were omitted from the revision. Council members asked whether areas that residents expected to be studied—near the Winn Dixie/distribution-warehouse corridor—had been analyzed. Monot said the team had defined a study area focused on where they expected the greatest benefit and that in places where his team’s modeled water surface converged with the existing FEMA map they terminated the revision. He agreed to “take another look” at a west-side tract that council members and residents said had earlier been shown on an older map as outside the flood zone.

Several residents also asked how the team had treated recent, observed flood events, including flooding during Hurricane Ida in 2021. A resident, Deborah Swenson of Woodward Subdivision, said she had experienced Ida flooding and asked whether event history and observed damage were incorporated into the study. Monot said the team reviewed the “history of flood structures and the dates” and attempted to correlate rainfall events to observed flooding as part of their analysis.

Planning & Zoning Commissioner Ron Matthews urged the city to consider an external peer review of the hydraulic model. “When you have another firm reviewing the model, the likelihood of getting what you want approved is much greater,” Matthews said, adding that an independent review can expedite FEMA concurrence. Monot said an external reviewer was not engaged for this LOMR.

Monot told the council the map that went to FEMA is a first draft and will almost certainly change in detail: “It’s guaranteed to change,” he said. After FEMA and the community resolve technical comments, the LOMR becomes preliminary and will be published for public comment; if there are no objections during the required comment period the revision may become effective several months later.

What’s next: Principal Engineering said it expects FEMA’s initial comments any day and will iterate with the agency. The city and the firm also agreed to re-examine the specific west-side tract identified by council members. Monot also confirmed the city will be notified in the public notice process when the preliminary map is published in the city’s legal journal, and he said staff can provide slides and mapping to residents for review in the interim.

Provenance: Presentation and Q&A begin at 00:10:19 and multiple related comments and public questions run through 00:38:14 in the meeting transcript.